Species notes relating to the collecting activites during the 3rd Archbold New Guinea Expedition in 1938-1939. The notes have been arranged into separate folders for each species. Each folder contains collection notes for the species by date; many folders also contain narrative species notes and transcription. The folder 'Hydromyinae' also contains a number of catalog sheets for both this and the 2nd Archbold Expedition of 1936-1937, as well as research notes and a partial manuscript draft. Richardson acted as mammalogist for the 3rd Archbold Expedition to New Guinea.